Portrait uniform lighting device

ABSTRACT

An accessory for uniformly illuminating a picture or the like comprising a treated film and a transparent cylindrically lenticulated support positioned between an illuminating source and a picture providing uniform illumination to the viewer and the method of making the same.

United States Patent Patented Jan. 11, 1972 PORTRAIT UNIFORM LIGHTING DEVICE 7 Claims, 5 Drawing Figs.

US. Cl 240/1 Int. Cl ..F2lv 11/00, F21v 5/00, F2lv 13/02 Field of Search 240/1, 1.3;

References Cited UNITED STATES PATENTS Champeau Poser Rackett MacNeille Luboshez Goodbar Cooper Primary Examiner Louis R. Prince Assistant Examiner- Denis E. Corr Attorney-Eugene F. Malin ABSTRACT: An accessory for uniformly illuminating a picture or the like comprising a treated film and a transparent 'cylindrically lenticulated support positioned between an illuminating source and a picture providing uniform illumination to the viewer and the method of making the same.

PATENTEDJAN! 1 m INVENTOR. FD ROYCE BTUTTLE. a W

ATTORNEY PORTRAIT UNIFORM LIGHTING DEVICE BACKGROUND OF THE INVENTION Most paintings, sketches, drawings, and the like are created with the artist working in well-illuminated surroundings, either natural or artificial. However, many works of art, as a practical matter, are illuminated with a small light that is positioned above and somewhat away from the face of the painting. The viewer, usually positioned directly in front of the painting, observes the work of art, therefore, in a light different than that in which the artist created the painting. This is due to the fact that the illumination intensity provided by the light source above the painting is not uniform over the surface of the painting. Therefore, the true expression of the artist is not realized by the viewer because the illumination intensity is distorted.

This invention relates to a novel accessory used in conjunction with a picture illumination source to insure a uniform illumination of the work of art, thereby insuring that the viewer will receive the full expression that was intended by the artist.

BRIEF SUMMARY OF THE INVENTION An accessory for providing uniform illumination comprising a transparent support provided with cylindrical lenticulations on one of its faces and on its other face with a plurality of optical density wedges orthogonal to and in registration with said lenticulations. The accessory is then positioned between a light source which is above and out from a picture face and the picture face itself. The support which may be a film has been so processed as to provide an optical density wedge in the focal plane of each individual lenticulation. Each accessory may be prepared on an individual basis for the particular work of art and illuminating source. The lenticulated transparent is provided with a light sensitive layer and is positioned to approximately the location of the intended illumination picture source. A light source positioned at the intended viewing angle illuminates the matte surface. Reflected light from the matte surface strikes the lenticulated support exposing the light-sensitive layer which is then processed to a negative.

It is an object of this invention to provide a lighting accessory for uniformly illuminating a picture, chart, or the like.

It is another object of this invention to provide a method of making a picture illuminating accessory.

It is yet another object of this invention to provide an accessory for picture illumination that is inexpensive to construct.

Still another object of this invention is to provide an accessory for illuminating a picture so that the viewer observes the work of art in the light intended by the artist.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 shows the illumination experienced by the viewer without applicant's invention.

FIG. 2 shows one embodiment of applicants invention.

FIG. 3 shows an arrangement for making the accessory embodying applicant's invention.

FIG. 4a shows the exposure gradient of the light-sensitive la er.

FIG. 4b is a cross section of the light-sensitive layer and a transparent lenticulated support.

PREFERRED EMBODIMENT OF THE INVENTION Referring now to the drawings and in particular FIG. I, a chart, painting, or other picture is shown illuminated by light source 1 1 which is surrounded by a reflector 12. The normal viewing angle is shown by the position of the observer 13. It is obvious because of the relative position of light source 11 with respect to painting 10 that the illumination intensity will decrease quite noticeably from the top of the painting. The effect of this illumination gradient will be that the observer at 13 will see the painting under a lighting condition that was not intended by the artist, who most likely painted the work of art under more uniform illumination conditions. FIG. 2 shows how this problem can be eliminated with the use of applicants invention. Applicant's device 14 is positioned between light source 11 and painting 10. Device 14 is comprised of a transparent cylindrically lenticulated base having a preprocessed film layer in the focal plane of the lenticulated elements of the transparent base. The film has been so processed as to provide a light-absorbing exposure gradient across each lenticulated element such that the film can be described as providinga plurality of optical density wedges orthogonal to and in the focal plane of each lenticulation. Light emanating from source 11 and reflecting surface 12 will penetrate the preprocess film layer and then be lenticulated by the transparent base of element l4 and will then reach'picture 10. The preprocessed film is placed ona flat surface of device 14 facing the light source 11. Thus The transparent base member has cylindrical lenticulations that are orientated parallel to the light source 11 and face picture 11. Thuswith the use of accessory 14, light source 11 in conjunction with the reflecting surface 12, will provide uniform illumination of picture 10.

FIG. 3 shows how the portrait lighting accessory is processed and made. A white matte surface 20, having the dimensions of the picture to be illuminated, is illuminated from the viewpoint of the observer with lamp 21 through a condenser lens 22 having, behind it, an apertured mask 23.

The lens 22 images the lamp 21 in a projection lens 24 which in turn images the aperture of the mask on the matte surface 20. Accessory 14, consisting of a light-sensitive layer 14-2 (FIG. 4b), is positioned next to the white matte surface 20' near the intended permanent illuminating source. The lightsensitive layer 14-2 may consist of a silver halide emulsion positioned on a flat surface of the lenticular support 14-1. The lenticular support has cylindrically orientated lenticulations parallel to and facing the white matte surface. The light-sensitive layer is exposed by the light reflected from the white matte surface. A timing means (not shown) provides for the desired exposure. After exposure and development, the negative image will appear as an density gradient without black lines 25' unless the exposure included light from a bright source 25 positioned along the bottom-edge of the matte surface 20. These black lines 25 insure sharp cutoff of the illumination at the bottom of picture 10 in FIG. 2. This gradually changing intensity pattern is repeated over each lenticulated segment. For each segment, the exposure intensity will begin at a maximum and will diminish to a minimum upon reaching the edge of the next lenticulated segment. In FIG. 4a, for example, the intensity pattern could vary from left to right, repeating at each black line 25. The portrait lighting accessory is custom made for each picture or chart size, the important variables being picture dimension, the location of the intended illuminating source, and intensity level desired. Transparent base 14-1 in FIG. 4 can be constructed from extruded glass or plastic. In many situations, it will be advantageous to employ individual lenses so that their contiguous surfaces may be silvered or otherwise opaqued 14-3 to increase efficiency as well as to prevent crosstalk, i.e., light from crossing over from one lens to another. Thus each lenticular element will transmit light that will provide a uniform illumination of the painting or picture.

The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention.

What is claimed is:

1. A device providing uniform illumination of a picture by a light source comprising:

a transparent lenticulated means,

' a film means providing an optical density wedge, said transparent lenticulated means and said film means so positioned with respect to said light source and said picture to provide uniform illumination of said picture to provide uniform illumination of said picture, wherein said transparent lenticulated means supports said film means, and is cylindrical; and said film means is preexposed at its location of intended use to a white, lighted surface representing said picture.

2. A device as in claim 1, wherein;

the density wedge of said film means is orthogonal to the cylindrical axis of and in the focal plane of said transparent lenticulated means.

3. A device as in claim 2, wherein;

said picture is disposed generally vertically, and

said light source is positioned above the forward of said picture.

4. A picture lighting accessory comprising;

a transparent support provided with cylindrical lenticulal positioning a cylindrically lenticulated support having a light sensitive layer on its plain surface with respect to a plain matte surface substantially in the same location as the accessory is to be used in picture illumination,

exposing said sensitive layer through the lenticulations to light reflected by said matte surface from light incident on said matte surface from the anticipated viewing angle, and

processing said exposed sensitive layer to a negative imagev 7. A method of producing an accessory for uniformly illuminating a picture which includes the steps of:

a. positioning a lenticulated support having a light-sensitive layer relative to a white surface representing said picture,

b. exposing said light-sensitive layer through said lenticulated support to light reflected from said white surface,

c. processing the exposed light-sensitive layer to a negative image, wherein said lenticulated support is positioned relative to said white surface at the position of intended use as said accessory. 

1. A device providing uniform illumination of a picture by a light source comprising: a transparent lenticulated means, a film means providing an optical density wedge, said transparent lenticulated means and said film means so positioned with respect to said light source and said picture to provide uniform illumination of said picture to provide uniform illumination of said picture, wherein said transparent lenticulated means supports said film means, and is cylindrical; and said film means is preexposed at its location of intended use to a white, lighted surface representing said picture.
 2. A device as in claim 1, wherein; the density wedge of said film means is orthogonal to the cylindrical axis of and in the focal plane of said transparent lenticulated means.
 3. A device as in claim 2, wherein; said picture is disposed generally vertically, and said light source is positioned above the forward of said picture.
 4. A picture lighting accessory comprising; a transparent support provided with cylindrical lenticulations and having an optical density wedge orthogonal to the cylindrical axis of and in the focal plane of each lenticulation.
 5. The accessory defined in claim 4, in which: said wedges have a taper density such that when said accessory is positioned between and with its lenticulations facing a generally vertically disposed picture and a source of light disposed above and offset forward of said picture uniform illumination of said picture is accomplished.
 6. The method of producing the accessory defined in claim 9 which includes the steps of: positioning a cylindrically lenticulated support having a light sensitive layer on its plain surface with respect to a plain matte surface substantially in the same location as the accessory is to be used in picture illumination, exposing said sensitive layer through the lenticulations to light reflected by said matte surface from light incident on said matte surface from the anticipated viewing angle, and processing said exposed sensitive layer to a negative image.
 7. A method of producing an accessory for uniformly illuminating a picture which includes the steps of: a. positioning a lenticulated support having a light-sensitive layer relative to a white surface representing said picture, b. exposing said light-sensitive layer through said lenticulated support to light reflected from said white surface, c. processing the exposed light-sensitive layer to a negative image, wherein said lenticulated support is positioned relative to said white surface at the position of intended use as said accessory. 